package com.hmdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.format.annotation.DateTimeFormat;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
public class RedisIdWorker {

    /**
     * 开始的时间戳
     */
    public static final long BEGIN_TIMESTAMP = 1640995200L;
    /**
     * 序列号位数
     */
    public static final long COUNT_BITS = 32;

    private StringRedisTemplate stringRedisTemplate;

    public RedisIdWorker(StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
    }

    public Long nextId(String keyPrefix) {
        //1. 生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond =  now.toEpochSecond(ZoneOffset.UTC);
        long timeStamp = nowSecond - BEGIN_TIMESTAMP;

        //2. 生成序列号

        //2.1 获取当前时间,精确到天
        String date = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));

        long count = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);

        //3. 拼接并返回

        return timeStamp << COUNT_BITS | count;

    }


}
